Method of manufacturing substrate structure with filling material formed in concave portion

ABSTRACT

Provided is a substrate structure including a substrate body, electrical contact pads and an insulating protection layer disposed on the substrate body, wherein the insulating protection layer has openings exposing the electrical contact pads, and at least one of the electrical contact pads has at least a concave portion filled with a filling material to prevent solder material from permeating along surfaces of the insulating protection layer and the electric contact pads, thereby eliminating the phenomenon of solder extrusion. Thus, bridging in the substrate structure can be eliminated even when the bump pitch between two adjacent electrical contact pads is small. As a result, short circuits can be prevented, and production yield can be increased.

TECHNICAL FIELD

The present disclosure relates to a substrate structure, and moreparticularly, to a substrate structure and a method for manufacturingthe same that increase the production yield.

BACKGROUND

With the evolution of semiconductor packaging technology, semiconductordevices have developed different types of packaging. Among which, ballgrid array (BGA), such as PBGA, EBGA, FCBGA, etc., is an advancedsemiconductor packaging technology, characterized by the use of apackage substrate to accommodate a semiconductor element, with solderballs arranged in a grid array on a back side of the package substrate.The entire packaging unit is electrically connected to externalelectronic device(s) through the soldering of these solder balls, sothat the same area of the unit on the carrier is able to accommodatemore input/output (I/O) connections in order to meet the need for highintegration of the semiconductor chips.

Furthermore, in order to be in line with the development in thedirections of compact, light, versatile, high-speed and high-frequencysemiconductor packages, the development of chips has been focused onareas of fine lines and small aperture.

As shown in FIG. 1, a traditional flip-chip semiconductor package 1includes a semiconductor chip 13 disposed on a packaging substrate 10.More specifically, the packaging substrate 10 includes a plurality ofelectrical contact pads 11, and the packaging substrate 10 and theelectrical contact pads 11 are covered with an insulating protectionlayer 12. The insulating protection layer 12 has a plurality of openings120 for exposing the corresponding electrical contact pads 11, such thata plurality of solder bumps 14 are joined with the electrical contactpads 11 in the various openings 120, allowing reflow of the varioussolder bumps 14 in order to connect with the semiconductor chip 13.

However, in subsequent heating process, the volume of the solder bumps14 will increase by about 30 to 50%, such that some of the solderingmaterials 140 of the solder bumps 14 may seep into the space between theinsulating protection layer 12 and the electrical contact pads 11 orbetween the insulating protection layer 12 and the packaging substrate10, resulting in solder extrusion. When the bump pitch between twoadjacent electrical contact pads 11 is small, the phenomenon of bridgingtends to happen, causing short circuits and decreasing product yield.

In order to avoid the above phenomenon of bridging caused by solderextrusion, a metal layer can be formed above the electrical contact pads11 to stop the permeation of the soldering materials 140. Morespecifically, as shown in FIG. 1′, a packaging substrate 10 includes abase 10 a and a circuit structure 10 b disposed on the base 10 a,wherein electrical contact pads 11 and a plurality of conductive traces100 are disposed on the circuit structure 10 b, and a metal layer 15 isformed on the electrical contact pads 11 in order to bond the solderbumps 14, wherein the metal layer 15 includes Ni/Pd/Au. The metal layer15 prevents the soldering materials from seeping between the insulatingprotection layer 12 and the electrical contact pads 11 or between theinsulating protection layer 12 and the packaging substrate 10 duringreflow of the solder bumps 14.

However, the method of using the metal layer 15 to cut off the solderingmaterials will inevitably increase the manufacturing cost of thepackaging substrate 10 by 10% to 25%. This is not economical.

Therefore, there is a need for a solution that addresses theaforementioned issues in the prior art.

SUMMARY

In view of the aforementioned shortcomings of the prior art, the presentdisclosure provides a substrate structure, which may include: asubstrate body; a plurality of electrical contact pads disposed on thesubstrate body, wherein at least one of the electrical contact padsincludes at least one concave portion; a filling material formed in theconcave portion; and an insulating protection layer formed on thesubstrate body and the filling material, wherein the insulatingprotection layer includes a plurality of openings exposing theelectrical contact pads.

In the above substrate structure, the insulating protection layerfurther includes at least one hole in communication with the concaveportion. For example, the filling material is formed in the hole.

In the above substrate structure, the filling material is integrallyformed with the insulating protection layer.

The present disclosure also provides a method for manufacturing asubstrate structure, which may include: providing a substrate bodyincluding a plurality of electrical contact pads; forming an insulatingprotection layer on the substrate body and the electrical contact pads,wherein the insulating protection layer includes a plurality of openingsexposing the electrical contact pads; forming at least one hole on theinsulating protection layer, wherein the hole extends into at least oneelectrical contact pad to form at least one concave portion on theelectrical contact pad in the hole; and forming a filling material inthe concave portion.

In the aforementioned method, the filling material is further formed inthe hole.

The present disclosure further provides a method for manufacturing asubstrate structure, which may include: providing a substrate bodyincluding a plurality of electrical contact pads, wherein at least oneof the electrical contact pads includes at least one concave portion;forming an insulating protection layer on the substrate body; andforming a filling material in the concave portion, wherein theinsulating protection layer includes a plurality of openings exposingthe plurality of electrical contact pads.

In the aforementioned method, the filling material is integrally formedwith the insulating protection layer.

In the aforementioned substrate structure and the methods, the concaveportion penetrates the electrical contact pad. In another embodiment,the concave portion is free from penetrating the electrical contact pad.

In the aforementioned substrate structure and the methods, theinsulating protection layer is composed of a material different from orthe same as the filling material.

The aforementioned methods further include forming a plurality ofconductive elements on the electrical contact pads in the plurality ofopenings to bond an electronic element. For example, the conductiveelements contain soldering materials.

In the aforementioned substrate structure and the methods, the fillingmaterial is a metal material or an insulating material. For example, theinsulating material is an underfill, a molding compound, a solderresistant material, polybenzoxazole (PBO), polyimide (PI), orbenezocy-clobutene (BCB).

In the aforementioned substrate structure and the methods, the concaveportion is at a corner of the substrate body.

It can be understood from the above that the substrate structure and themethods of the present disclosure essentially includes forming concaveportions in which a filling material is filled on the electrical contactpads, such that the filling material prevents the soldering materialsfrom permeating along the interfaces of the insulating protection layerand the electrical contact pads, thereby eliminating the phenomenon ofsolder extrusion. Thus, compared to the prior art, bridging in thesubstrate structures can be eliminated even when the bump pitch betweentwo adjacent electrical contact pads is small. As a result, shortcircuits can be prevented, and production yield can be increased.

Moreover, the substrate structure of the present disclosure does notneed an additional metal layer formed on the electrical contact pads asrequired in the prior art, thereby reducing the manufacturing cost ofthe substrate structure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure can be more fully understood by reading thefollowing detailed description of the preferred embodiments, withreference made to the accompanying drawings, wherein:

FIG. 1 is a cross-sectional diagram illustrating a traditionalsemiconductor package;

FIG. 1′ is a cross-sectional diagram illustrating a portion of anothertraditional semiconductor package;

FIGS. 2A to 2C are cross-sectional diagrams illustrating a method formanufacturing a substrate structure in accordance with a firstembodiment of the present disclosure, wherein FIG. 2B′ is anotherembodiment of FIG. 2B; FIG. 2B″ is a partial top view of FIG. 2B′; FIG.2C′ is another embodiment of FIG. 2C; and FIG. 2C″ is a partial top viewof FIG. 2C;

FIGS. 3A and 3B are cross-sectional diagrams illustrating a method formanufacturing a substrate structure in accordance with a secondembodiment of the present disclosure; and

FIGS. 4A and 4B are cross-sectional diagrams illustrating a method formanufacturing a substrate structure in accordance with a thirdembodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present disclosure is described by the following specificembodiments. Those with ordinary skills in the arts can readilyunderstand other advantages and functions of the present disclosureafter reading the disclosure of this specification. The presentdisclosure may also be practiced or applied with other differentimplementations. Based on different contexts and applications, thevarious details in this specification can be modified and changedwithout departing from the spirit of the present disclosure.

It should be noted that the structures, ratios, sizes shown in thedrawings appended to this specification are to be construed inconjunction with the disclosure of this specification in order tofacilitate understanding of those skilled in the art. They are notmeant, in any ways, to limit the implementations of the presentdisclosure, and therefore have no substantial technical meaning. Withoutaffecting the effects created and objectives achieved by the presentdisclosure, any modifications, changes or adjustments to the structures,ratio relationships or sizes, are to be construed as fall within therange covered by the technical contents disclosed herein. Meanwhile,terms, such as “up”, “down”, “bottom”, “first”, “second”, “a” and thelike, are for illustrative purposes only, and are not meant to limit therange implementable by the present disclosure. Any changes oradjustments made to their relative relationships, without modifying thesubstantial technical contents, are also to be construed as within therange implementable by the present disclosure.

FIGS. 2A to 2C are cross-sectional diagrams illustrating a method formanufacturing a substrate structure 2 in accordance with a firstembodiment of the present disclosure.

As shown in FIG. 2A, a substrate body 20 including a plurality ofelectrical contact pads 21 is provided, and an insulating protectionlayer 22 is formed on the substrate body 20 and the electrical contactpads 21.

In this embodiment, the substrate body 20 is a circuit structure. Forexample, the substrate body 20 can be a circuit board having a pluralityof dielectric layers and a plurality of circuit layers, and theelectrical contact pads 21 are electrically connected with conductivetraces 200. The electrical contact pads 21 and the conductive traces 200form the outermost circuit layer, which is disposed on top of theoutermost dielectric layer and electrically connected with other circuitlayers. The material used for forming the dielectric layers can beprepreg materials.

Furthermore, in another embodiment, the substrate body may include abase and a circuit structure disposed on the base, and electricalcontact pads 21 and conductive traces 200 are disposed on the circuitstructure. The base can, for example, be a semiconductor substrate, suchas a wafer, a chip, an interposer with Through-Silicon Vias (TSVs). Thecircuit structure includes a plurality of dielectric layers and aplurality of redistribution layers (RDLs), wherein the electricalcontact pads 21 and the conductive traces 200 are provided on theoutermost dielectric layer and electrically connected with other circuitredistribution layers. Alternatively, the electrical contact pads 21 andthe conductive traces 200 are part of a circuit redistribution layer.

Moreover, the insulating protection layer 22 includes a plurality ofopenings 220 for exposing the corresponding electrical contact pads 21.More specifically, the material for the insulating protection layer 22can be a solder resistant material or a dielectric material, wherein thedielectric material can, for example, be polyimide (PI),benezocy-clobutene (BCB) or polybenzoxazole (PBO).

As shown in FIG. 2B, a plurality of holes 221 are formed in theinsulating protection layer 22. These holes 221 extend into theelectrical contact pads 21, such that at least one concave portion 210is formed on the electrical contact pad 21 in each hole 221, whereinthese holes 221 are at the periphery of the openings 220.

In this embodiment, the hole 221 and the concave portion 210 are incommunication with each other. For example, a hole 221 and a concaveportion 210 are formed by laser simultaneously, such that the shape ofthe hole 221 matches that of the concave portion 210. It can beunderstood that the holes 221 and the concave portions 210 can be formedby etching.

In addition, the concave portion 210 penetrates the electrical contactpad 21, such that the surface of the substrate body 20 is exposed fromthe concave portion 210. Alternatively, a concave portion 210′ does notpenetrate the electrical contact pad 21, as shown in FIG. 2B′. Forexample, the thickness of the electrical contact pad 21 is about 25 μm,and the depth (i.e., the depth of the laser drill hole) of the concaveportion 210′ is about 10 to 15 μm.

Moreover, the concave portions 210 and 210′ are at the edge of theelectrical contact pads 21, and the planar shape of the electricalcontact pads 21 viewed from the top can be various geometric shapes. Forexample, as shown in FIG. 2B″, when the planar shape of the electricalcontact pad 21 viewed from the top is a circle, then the planar shape ofthe concave portion 210 may, for example, be a ring shape, a ring shapewith a gap or arcs with at least two intervals. Thus, there can bevarious shapes and forms for the electrical contact pads 21 and theconcave portions 210 and 210′, and the present disclosure is not limitedto the abovementioned.

In addition, the width of the hole 221 (or the width of the concaveportion 210 or 210′) may be 5 to 25 μm, as shown in FIG. 2B′.

As shown in FIG. 2C, filling materials 23 is formed in the concaveportion 210 and the holes 221, thereby forming the substrate structure2.

In this embodiment, the filling materials 23 are made of the same ordifferent material as the insulating protection layer 22, that is, anymaterial can be used as the filling materials 23 as long as they blocksthe flow of the soldering material, such as a metal material or aninsulating material; the present disclosure is not limited as such.

Moreover, a substrate structure 2′ shown in FIG. 2C′ can be obtained ifthe manufacturing process is continued from FIG. 2B′.

FIGS. 3A and 3B are cross-sectional diagrams illustrating a method formanufacturing a substrate structure 3 in accordance with a secondembodiment of the present disclosure. The method of this embodiment isdescribed from the manufacturing process in FIG. 2B, that is, the methodis the same up until the stage described in FIG. 2B, and the differencesare illustrated below.

As shown in FIG. 3A, a plurality of conductive elements 24 containingsoldering materials are formed on the electrical contact pads 21 in theopenings 220, so as to bond an electronic element 30 via the conductiveelements 24, wherein each of the conductive elements 24 is electricallyconnected with a corresponding electrical contact pad 21.

In this embodiment, the electronic element 30 is an interposer withTSVs, a circuit board, an active component, a passive component or acombination thereof, wherein the active component can be, for example, asemiconductor chip or a wafer, and the passive component can be, forexample, a resistor, a capacitor or an inductor. As an example, theelectronic element 30 is an active component, which includes an activesurface 30 a and a non-active surface 30 b opposite to each other. Theactive surface 30 a includes a plurality of electrode pads 300, so thatthe electronic element 30 is bonded to the conductive elements 24through corresponding electrode pads 300.

Moreover, the conductive elements 24 can be solder bumps, copper bumpscoated with soldering materials or any other bumps containing soldermaterials.

As shown in FIG. 3B, filling materials 33 are formed in the concaveportions 210 and the holes 221, and an encapsulating layer 31 is formedbetween the active surface 30 a of the electronic element 30 and theinsulating protection layer 22, thereby producing an electronic package3′.

In this embodiment, the filling materials 33 and the encapsulating layer31 are integrally formed. For example, the filling materials 33 and theencapsulating layer 31 are formed by the same filling process or moldingprocess, so the material of the filling materials 33 and the material ofthe encapsulating layer 31 are the same. For example, they are bothformed of underfill or molding compound (e.g., epoxy resin).

FIGS. 4A and 4B are cross-sectional diagrams illustrating a method formanufacturing a substrate structure 4 in accordance with a thirdembodiment of the present disclosure. The difference between thisembodiment and the last embodiment is in the manufacturing process ofthe concave portion, so the differences are illustrated below, whilesame parts are not repeated.

As shown in FIG. 4A, a substrate body 20 including electrical contactpads 21 is provided, and the electrical contact pads 21 have a pluralityof concave portions 410.

In this embodiment, concave portions 410 are formed in the electricalcontact pads 21 by etching or laser process. It can be understood thatelectrical contact pads 21 with concave portions 410 can be formeddirectly by electroplating or coating. Moreover, the concave portions410 can be chosen to penetrate or not penetrate the electrical contactpads 21.

As shown in FIG. 4B, an insulating protection layer 22 is formed on thesubstrate body 20, and a plurality of filling materials 43 are formed inthe concave portions 410.

In this embodiment, the insulating protection layer 22 has a pluralityof openings 220 for exposing corresponding electrical contact pads 21.

Moreover, the filling materials 43 and the insulating protection layer22 are formed integrally. For example, the filling materials 43 and theinsulating protection layer 22 are formed by the same coating process,so the materials of the filling materials 43 and the insulatingprotection layer 22 are the same. For example, they are both made of adielectric material or a solder resistant material. Alternatively, thefilling materials 43 and the insulating protection layer 22 can be madeof the same material but separately. It can be understood that thefilling materials 43 and the insulating protection layer 22 can also bemade of different materials and made separately.

In the substrate structures 2, 2′, 3 and 4 of the present disclosure,concave portions 210, 210′ and 410 are formed on the electrical contactpads 21, such that filling materials 23, 33 and 43 are formed in theconcave portions 210, 210′ and 410, so in the subsequent heatingprocess, the flow of the soldering materials of the conductive elements24 are blocked by the filling materials 23, 33 and 43, preventing thesoldering materials of the conductive elements 24 from permeating alongthe interfaces of the insulating protection layer 22 and the electricalcontact pads 21. Thus, bridging in the substrate structures 2, 2′, 3 and4 can be eliminated even when the bump pitch between two adjacentelectrical contact pads 21 is small, avoiding short circuits. Thus,compared to the prior art, the substrate structures 2, 2′, 3 and 4 ofthe present disclosure are in line with the developments towards morecompact, lighter, more versatile, higher speed and higher frequencysemiconductor chips, and production yield can be increased.

Moreover, since the substrate structures 2, 2′, 3 and 4 of the presentdisclosure do not require forming a solder material blocking layer(metal layer) on the electrical contact pads 21 as described in theprior art, the manufacturing cost of the substrate structures 2, 2′, 3and 4 can thus be effectively controlled, and is cost effective.

In addition, in the substrate structures 2, 2′, 3 and 4 of the presentdisclosure, the concave portions 210 can be formed on all of theelectrical contact pads 21. However, it can be understood that theconcave portions 210 can be formed only where the bump pitch is smalleror stress is higher (e.g., at the four corners of the substrate body20), as shown in FIG. 2C″, further reducing the production time andcost.

The present disclosure further provides a substrate structure 2, 2′, 3or 4, including a substrate body 20, a plurality of electrical contactpads 21, a filling material 23, 33 or 43, and an insulating protectionlayer 22 formed on the substrate body 20 and the filling material 23, 33or 43.

The electrical contact pads 21 are formed on the substrate body 20,wherein at least one electrical contact pad 21 includes at least oneconcave portion 210, 210′ or 410.

The filling material 23, 33 or 43 is formed in the concave portion 210,210′ or 410.

The insulating protection layer 22 includes a plurality of openings 220for exposing corresponding electrical contact pads 21.

In one embodiment, the insulating protection layer 22 further includesholes 221 in communication with the concave portion 210 or 210′, and thefilling materials 23 or 33 are formed in the holes 221.

In one embodiment, the material of the filling material 23 or 33 isdifferent from that of the insulating protection layer 22.

In one embodiment, the material of the filling material 23 or 43 is thesame as that of the insulating protection layer 22.

In one embodiment, the filling material 43 is integrally formed with theinsulating protection layer 22.

In one embodiment, the substrate structure 3 further includes aplurality of conductive elements 24 disposed on the electrical contactpads 21 of the openings 220 for combining with an electronic element 30.

In one embodiment, the material of the filling material 33 can be madeintegrally with and of the same material as an encapsulating layer 31formed between the electronic element 30 and the insulating protectionlayer 22.

In one embodiment, the material of the filling material 23, 33 or 43 canbe a metal material or an insulating material, and the insulatingmaterial can be an underfill, a molding compound, a solder resistantmaterial, polybenzoxazole (PBO), polyimide (PI), or benezocy-clobutene(BCB).

In summary, the substrate structure and the manufacturing for thesubstrate structure of the present disclosure avoids the phenomenon ofsolder extrusion through the use of the concave portions and the fillingmaterials. As a result, the substrate structure of the presentdisclosure has the development potential of being compact,multi-functional and with high speed and high frequency, and productionyield can be increased while the manufacturing cost of the substratestructure can be effected controlled.

The above embodiments are only used to illustrate the principles of thepresent disclosure, and should not be construed as to limit the presentdisclosure in any way. The above embodiments can be modified by thosewith ordinary skill in the art without departing from the scope of thepresent disclosure as defined in the following appended claims.

1-13. (canceled) 14: A method for manufacturing a substrate structure,comprising: providing a substrate body including a plurality ofelectrical contact pads; forming an insulating protection layer on thesubstrate body and the electrical contact pads, wherein the insulatingprotection layer includes a plurality of openings exposing theelectrical contact pads; forming at least one hole on the insulatingprotection layer, the hole extending into at least one of the electricalcontact pads to form at least one concave portion on the electricalcontact pad; and forming a filling material in the concave portion. 15:The method of claim 14, wherein the filling material is further formedin the concave portion. 16: A method for manufacturing a substratestructure, comprising: providing a substrate body including a pluralityof electrical contact pads, wherein at least one of the electricalcontact pads includes at least one concave portion; and forming aninsulating protection layer on the substrate body, and forming a fillingmaterial in the concave portion, wherein the insulating protection layerincludes a plurality of openings exposing the electrical contact pads.17: The method of claim 16, wherein the concave portion is formed topenetrate the electrical contact pad. 18: The method of claim 16,wherein the concave portion is formed free from penetrating theelectrical contact pad. 19: The method of claim 16, further comprisingforming a plurality of conductive elements on the electrical contactpads exposed from the openings to bond an electronic element. 20: Themethod of claim 16, wherein the concave portion is formed at a corner ofthe substrate body.